*Note: DIYLILCNCv2 is still totally in beta. We have a functioning prototype, but the design is ever-evolving (so the design may change after you buy parts). While you can do-it-yourself, there are some challenging steps that involve working with dangerous levels of electricity. If you are unsure about something, reach out to a local university or hackerspace for tips.

Although Taylor Hokanson and Chris Reilly are the principle researchers on the project, DIYLILCNC would not have been possible without the help and support of many individuals and institutions. Much of the DIYLILCNCv1 design was derived directly from two instructables posts (one, two) by oomlout. We improved upon the design with funding from The School of the Art Institute of Chicago, with particular help from Chad Gerth, Brian Stansbury and all the fantastic faculty and staff in the AIADO department.

DIYLILCNC is an open source initiative tasked with increasing the accessibility of CNC tooling/education for the broadest possible audience. As such, all of the intellectual property generated by the project is free to download, remix and redistribute, even for commercial gain (details). All we ask is that credit be maintained in all derivative works, and that these works carry the same license. If you’re not sure what this means, feel free to get in touch.

PS: For this and many other open source projects, we like to rely on the “smell test” when in doubt. Not too long ago, an enterprising web denizen copied our entire DIYLILCNC v1 design document and submitted it to an online contest. In some ways, this was not explicitly in conflict with the letter of our Creative Commons license. After all, this individual did credit our authorship (even if they did move the details from the first to the last page of their submission). Naturally, we felt that this violated the spirit of our license and had the contest entry taken down.

Much of our ability to produce a second-generation version of the DIYLILCNC depended on financial help from our 2011 Kickstarter Campaign. Our heartfelt thanks goes out to these folks for helping us get the job done:

We’re doing our best to support our two main build communities: those working inside and those working outside the United States (bonus cautionary tale). We recommend that both groups use Metric parts wherever possible, though certain Metric items are more expensive and difficult to source in the US. We’ll provide Imperial alternatives for these items (such as the aluminum angle rails), but make sure to note when Imperial substitutions require a different set of matching gantry panels.

Many of the tools listed below are recommended. Although you could probably assemble this kit entirely with hand tools (assuming you already had the panels CNC milled), a jigsaw and cordless drill would really help.

The gantry panels that make up a DIYLILCNCv2 are made of CNC milled plywood. The thickness of this material is not critical; you can use anything in the neighborhood of .5″/12mm. Plywood with more layers will improve rigidity and increase cost (marginally).

We don’t currently have a source for fabrication, but we hope to offer that service soon. In the meantime, all are welcome to download the CAD files for free. Many universities and cabinetry shops have CNC mills. Prices will vary widely, so do your homework.

A robot isn’t much use without a brain. You’ll need a PC with a parallel port to run the DIYLILCNC. Wish you could use USB? So do we, and we researched long and hard before choosing parallel. In a nutshell, parallel will allow you to use an old underpowered PC to keep things cheap. This communication protocol also allows for real-time signalling, which is particularly crucial in an open-loop control system. While you can find USB stepper-control boards out there, they tend to be underpowered for this application.

We’ve kept the PC out of the budget because this type of box can often be had for free. Alternately, you might choose to build your own on the cheap.

Mount a Belt Tensioning Assembly in the appropriate spot on a Shoulder Block Interior Panel.

You should also add a rod bushing to the center hole at this time, oriented so that the lip is on the same side as the Belt Tensioning Assembly. This part should be snug but not tight – if you have to push too hard, ream the hole a bit (but not too much!)

Attach the Shoulder Block Top Panel to the Shoulder Block Interior Panel. Be sure to keep the Belt Tensioner facing out/towards you. Note how the triangular “fin” of Shoulder Block Top Panel is pointing in the same as the Belt Tensioner (to the left).

Pass two pieces of 24″ | 610mm aluminum angle stock through the center of the Shoulder Block Assembly. Add a Y Rail Spacer and an Y Rail Mounting Plate, then fix in place with a hand-tightened bolt/nut combo.

Slide the Z Sled Rails through the arrow-shaped slots in the Z Cart Top. Push them until they are securely seated in the diamond-shaped indentation in the Z Cart Bottom. Add two Z Rail Spaces to the top and the bottom of the rail pair to fix in place.

Insert two Aluminum X Rails through the Exterior Panel of the left-hand Shoulder Block, and continue to push until about 12″ | 300mm protrudes from the Interior Panel. Now push the X Motor Assembly between the rails as shown.

Insert a length of 1/4″ rod in the Exterior Panel of the left-hand Shoulder Block and push until about 1″ | 50mm is exposed at the Interior Panel. Now pass the rod through a belt pulley, then continue to push until the rod makes contact with the motor spindle. Fix the rod in place with a coupler, but let the pulley float for now.

Pass the timing belt through the Belt Slot in the front left Vertical Brace. Continue to pull the belt until you can pass it first around the belt tensioner, then around the pulley, and finally through the Belt Slot at back rear. Fix in place with a pair of Belt Clamp Panels. Cut the pulley to length, leaving yourself a little extra on either end for adjustment. The biming belt should be somewhat taught and equally tight on both sides. Experiment to find the right setting for your rig. Once the belt is taught, fix pulleys in place on drive rod.

Repeat these steps for both the right-hand Shoulder Block and the Z Cart.

Open an .NC file with EMC2. Jog the tool to a safe middle range, zero each axis, then run the job up in neutral territory. Once you’re confident the scaling is right, re-zero so that your tool actually meets your material.

From the OS desktop, run APPLICATIONS > CNC > Stepconf Wizard. See this link for a page-by-page walk-through of all EMC2 Stepconfig settings.

Most of the settings in Stepconfig are determined by the HobbyCNC controller board and the motors it ships with. One key setting, however, called “leadscrew pitch”, is determined by the hardware that you happened to purchase with your build.

X/Y: The pulleys on the DIYLILCNC are mounted directly on the motor shaft, so the system will travel a linear distance equal to the outer diameter of the pulley for each turn of the motor. Thus, LEADSCREW PITCH = 1 / CIRCUMFERENCE.

Z: Figuring Z-axis ratios is a little more challenging. Start with the following equation: